497 
fxus65 kslc 052142 
afdslc 


Area forecast discussion 
National Weather Service Salt Lake City Utah 
340 PM MDT Sat Jul 5 2008 


Synopsis...an upper level trough moving through the northern 
rockies will push a weak cold front across northern Utah Sunday. A 
dry and stable west northwest flow aloft will follow for the early 
and middle portion of the coming week. 


&& 


Discussion...moisture moving northeast around the upper high 
centered near The Four-Corners covers much of southern and eastern Utah this 
afternoon. The most active convection has developed along the western 
edge of the moisture plume. Water vapor imagery suggests that a weak 
vorticity lobe may exist over the Utah/NV/AZ triple point. Weak 
dynamic lift along with strong heating and moisture has led to 
widely scattered convection over SW Utah. 


The upper trough moving east through the northern rockies late 
tonight/Sunday will force the upper high further southeast...and take much 
of the moisture into extreme southeast and eastern Utah Sunday. The weak 
surface front associated with the northern rockies trough will press into 
northern Utah late tonight or early Sunday morning. Behind the front 
modest cooling around 700mb along with some middle-level moisture and 
dynamic lift could result in spotty precipitation up north during the day 
on Sunday. Pockets of convection also a good bet for eastern Utah in the 
residual moisture. The remainder of the forecast area likely to be 
dry and drier air pushes into west/cntrl-SW Utah out of eastern Nevada. 


A generally dry and stable pattern shaping up for at least the early 
and middle portions of the coming week. Heights are prognosticated to build 
across the eastern Pacific...leaving the Great Basin under a light west-northwest 
flow aloft. With little or no dynamic lift and fairly warm middle-level 
temperatures...doubt that anything more than isolated mountain convection 
will develop during any given afternoon. The eastern Pacific high could 
retreat far enough west by next weekend to let some moisture return 
north into the basin. For now will mention some showers/storms at 
the end of the forecast period. 


&& 


Fire weather...a weak upper level disturbance is moving across 
southern Utah this afternoon and interacting with a plume of 
moisture extending north out of Arizona. This is resulting in a band 
of clouds and scattered showers across south central and southeast 
Utah this afternoon and this has kept relative humidities from 
dropping in this area. However...gusty southwest winds and dry 
conditions are again in place across the southwest corner of the 
state and critical fire weather conditions will persist into the 
evening hours. 


Another upper level disturbance will impact Utah on Sunday...pushing 
the cold front through northern Utah Sunday. This will bring a little 
cooler weather to the northern third of the state. Winds aloft are 
expected to be lighter and critical fire weather conditions are not 
anticipated on Sunday. As this system moves through Utah isolated 
valley convection will be possible across northern Utah with 
scattered mountain convection across the central and north. For the 
early portion of the week the upper level ridge builds back into 
Utah with temperatures slowly climbing across the north and 
afternoon relative humidities once again dropping to critical levels 
in many valley locations in the afternoon. However...the ridge over 
the region will likely bring lighter winds to the area through the 
early portion of the week. By the end of the week guidance 
indicates there is the potential for an upper level trough to 
approach the West Coast. This would result in increasing winds and 
the potential for additional moisture to move north into the state. 


&& 


Aviation...north to northwest winds will shift to south to 
southeast at the kslc terminal between 03-04z tonight. 
Otherwise...mostly clear skies will continue into the nighttime 
hours. 


&& 


Slc watches/warnings/advisories... 
Utah...red flag warning until 9 PM this evening for utz435-439. 
Wyoming...none. 


&& 


$$ 


Conger/Graham/Kruse 


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